Could Life Exist on Mini-Neptunes?

It would certainly make the search for life outside Earth a lot easier if life could exist on the class of planets astronomers have dubbed "Hycean" worlds. Hycean planets are otherwise known as mini-Neptunes because of their diameter (bigger than Earth, smaller than Neptune) and their make-up, having large hydrogen atmospheres. These mini-Neptunes don't actually have much more mass than the Earth.

According to a new study, scientists believe that Hycean planets may actually be a prime source for life. The reason is simple: These planets likely have oceans of liquid water underneath the hydrogen atmosphere, and we all know life loves liquid water. In addition, Hycean planets have proved to be quite common in the universe, and it is believed that detecting biosignatures in the atmospheres of these planets would actually be easier than on standard terrestrial worlds. The plan is to use the James Webb telescope (which is finally ready for launch) on a number of Hycean planets within 200 light-years of Earth, scanning them for molecules consistent with life. It wouldn't be definitive evidence, but it would be closer than we've come yet, and that would be big news.

Bad News for Martian Life Enthusiasts

In the past few years, the Mars Express orbiter scanned the Martian polar ice caps with radar and discovered evidence of liquid water in the form of super-salty lakes below the surface. In terms of finding life, that's a good thing. Where there's water, there's probably life. But there's a problem with that, according to a new study. In order for liquid water to exist at the poles, it would require a lot more energy than what Mars is capable of providing, at least as far as we know.

There's another problem, according to the study, in that there's a type of clay, abundant on Mars, that can give the same radar signature as water. So, let's consider the evidence; either the radar signature came from something known to exist on Mars in significant quantities or there are lakes down there which defy the laws of physics and thermodynamics. Perhaps there is still life on Mars, but the polar lakes theory is a dead end.

Bad News for Venusian Life Enthusiasts

A few months ago scientists found evidence of phosphine gas in the Venusian atmosphere. Phosphine is a gas produced by microbial life, and finding it on Venus was a big enough deal that nonscience-specific news organizations picked up on it, like the New York Times. 

Perhaps unsurprisingly, the initial discovery of phosphine has turned out to be more complicated and not nearly as good for the prospect of Venusian life. Let's start with the big bummer: It wasn't actually phosphine that was detected. Spectral analysis is tough, and sometimes one chemical can be mistaken for another. That's what happened here. The phosphine was actually sulfur dioxide, which is both incredibly common on Venus and not associated with life in any way. In addition, that signal was coming from much higher up in the atmosphere, at an altitude where the sun's radiation would almost immediately destroy phosphine. So yeah, while there may very well be life in the Venusian atmosphere, we're still a long way off from finding it.

We May Find Alien Life Very Soon

But don't hold your breath for intelligent life.

That's the crux of a pair of articles that are on the front page of Space.com today. I thought it was kind of funny that they were sharing space with one being so optimistic and the other ... being decidedly less so.

Let's start with the positive, which comes from a discussion at the International Astronautical Congress. Basically, a lot of really smart people think we'll find life in our solar system very soon. As in, 10 or 15 years. It'll probably be on Mars, but who knows, maybe Enceladus or Europa would surprise. I thought it was funny that someone brought up Frank Drake, the man behind the infamous Drake equation, which seeks to put a number of possible technological civilizations based on the likelihood of a variety of factors, like the number of habitable planets, the number of planets that can sustain life, and the number of planets where life lasts long enough to reach intelligence.

And that brings us to the second article. It's nothing I haven't seen before, true technological intelligence is going to be incredibly rare because there are so many factors that have to go right, blah blah blah. I have two problems with this line of thinking. One: Anything that puts Earth on a pedestal is suspicious. We should always try to avoid thinking of ourselves as important, or at the center of the universe. Two: We have absolutely no idea how common the things that led to the rise of life on Earth actually are. We're only just now able to get some idea of the number of habitable worlds in the galaxy, and there are so many other steps involved. We have a sample size of one. We can't know how common intelligent life is because we have no idea how common life is. Concluding something when we're missing half a dozen variables is silly.

Anyway, that's my rant for the day.

Could Venus Harbor Native Life?

Yes, this is a question people are asking. And it may not be quite as crazy as you might think.

Clearly, there isn't going to be any life on the surface of Venus. It's about 750 degrees too hot there for even the hardiest of single-celled organisms. For life to exist on the Venusian surface, it would have to be beyond anything we've ever seen. Almost beyond the realm of fiction. The upper atmosphere of Venus may be a different story. The pressure and temperature is actually fairly hospitable if you're at the right altitude.

Of course, what would a crazy theory be without evidence? And this time we have some interesting observations from the Japanese space probe Akatsuki, which observed periodic dark patches in the upper atmosphere rich in sulfur. The particles in these patches have the similar dimensions to terrestrial bacteria, and the periodic nature of the patches could indicate a phenomenon similar to algae blooms here on Earth.

So is there life on Venus? Can we add it to the list of places in the Solar System where life likely exists? I'd say probably not. But there's a chance, and it's probably worth checking out. And since Venus is pretty close, we may check it out sometime in the next 10-15 years. We'll see. I won't hold my breath, but I have to say, it would be kind of funny if the first extraterrestrial life we found was on Venus.

What If There's Life on Mars?

It's a question we've asked before, and we'll probably ask again. What does humanity do with Mars if we happen to discover native Martian life? I think it's worthwhile to mention it now, because Mars has been on the news as of late. President Obama recently stated that it should be a goal for the United States to reach Mars by 2030, and Elon Musk wants to colonize Mars, sooner rather than later. Of course, that colonization plan is wildly ambitious and almost certainly completely unrealistic, but the fact remains that very big people are very excited about Mars.

This is probably not Martian life. But what if there is Martian life?

That brings us to an article recently published in Astrobiology (available for free until November 15) which reevaluates data collected by the Viking space probes. There is a possibility that the results for the experiment meant to detect life were actually positive, not negative. This is not the consensus view in the scientific community, of course, but there is an apparent case for argument. Also, the study authors argue, even if the Viking results are actually negative, enough evidence has stacked up over the years that the possibility of native Martian life cannot be ignored.

And this is where that big question comes in again. What do we do with Mars if we find life there? Brazenly moving in regardless seems like the wrong answer. Earth microbes are not currently adapted to life on Mars, but there's no reason to assume they wouldn't, or couldn't, make life work there. And once they moved in, it would almost certainly mean the extermination of native Martian life. Sure, the Martian microbes might give a few good punches back, maybe cause an illness or two, but why would Martian life be any less susceptible to Earth germ warfare then the American Indians were when the Europeans moved in? Sure, they gave the Europeans syphilis, which killed a few million, but an STD could not possibly do as much damage as smallpox or measles did to the native American population. What the Europeans did in the Americas is generally not viewed as a good thing. We killed millions and drove cultures either to extinction, or broke them. I really don't think that we want to do the same thing on Mars.

I'm sure we'll hear the argument that Martian life is surely primitive compared to Earth life, and that colonizing Mars is more important for the survival of the human race. Maybe those people will say that Martian life will be maintained in specific areas set aside for it, places where people won't go. Ignoring the obvious historical parallels, that's dangerous thinking. Where does the line stop then? How advanced does the life have to be before we risk contaminating the environment with Earth life? Bacteria? Multicellular? Big enough to see? There's a risk setting that line anywhere other then "If there's life there, humans won't go there." What if we decide we don't like where we set the line, and decide to move it further down? It would probably be best not to give ourselves the chance to equivocate and make a blanket rule: if a planet or moon has native life, we won't colonize there.

If only it were that simple. I have a hard time believing the ethical concerns of a few people over some bacteria is going to stop the colonization of Mars, or any place, really. Let's go a couple hundred years down the road, to a hypothetical first interstellar mission. We've finally done it, we've finally found a planet that's just like Earth. Green plants, blue skies, pleasant temperatures, exotic animal life, the works. There is no way we don't plop ourselves down and make that planet a new home. If we can risk the ecosystem of this planet, why can't we do the same for any world? And who knows, maybe in the future we'll come up with some crazy technology that will prevent the cross-contamination of microbes. The facts are these: humanity can't stay on Earth forever, and I doubt our descendants are going to want to spend their lives on cold, dead rocks or floating through space in metal cans. Planet colonization is in our future, and we might as well get to it sooner rather than later.

We haven't really gotten anywhere, have we? I guess it wouldn't be an ethical dilemma if some guy on the internet could solve it in a few paragraphs. I guess it comes down to whether or not humanity is comfortable with playing god with lesser species. We always have been in the past, and I don't see that changing much. A lot of people are concerned about what global warming is going to do to the planet, but I wonder how much of that is actual concern for the planet, and not self-preservation. Let's face it, we're selfish. There's nothing wrong with that, all life works to preserve itself, even at the cost of other species. I guess it really boils down to how you think about humanity. If you think about the human race as just another species fighting for survival, it's a no-brainer. If you think about the human race as more than that, if you think we have greater responsibilities than our own survival, well, that's a no-brainer as well.

Geez, this got pretty heavy. I'll try to keep things a little less dense next time.

To Find Life on Mars, Follow the...Salt?

When it comes to finding life on Mars, NASA has had a strategy: follow the water. It makes sense, life as we know it requires liquid water, so it would make sense that if liquid water could be found, that would be the logical place to look for any Martian life. We've even managed to find some liquid water in the form of the recurring slope lineae. However, some new research suggests that following the water may not be the best strategy. Their suggestion? Look for life in the driest, saltiest places.

This sounds very counter-intuitive, but it does make a certain amount of sense, considering how microbial life has adapted to the driest conditions here on Earth. In these hyperarid regions, life survives by going underground, living underneath salty crusts that absorb water directly from the air. There is a possibility that as Mars dried up and microbes huddled together in the last bits of liquid brine just below the surface, they evolved in a similar fashion to Earth microbes in a similar situation, subsisting on the small amount of water in the Martian atmosphere. The researchers also suggest that these environments probably dried up for the last time recently, and perhaps some still exist. It's not the most dignified way for life to get by, but to go for so long in such a hostile place would be impressive nonetheless.

New Species of Frog Discovered

This is just a regular old leopard frog.

This doesn't sound like a big deal at first. I mean, it'll just be another random little tropical frog that no one will ever see, right? Well, no. It's nothing special either, it doesn't spit acid from its eyeballs or hunt birds or something spectacular, it's just another frog. So, why write about it? Well, this new species of frog is called the Atlantic Coast leopard frog, and it resides in one of the biggest cities on Earth: New York City. It is remarkable how even in the most dense urban areas, we can still manage to discover new species. Again, this isn't a new bacteria, or some simple animal like a nematode or worm, it's a frog. You can see them, you can hear them, it's an animal you could go out and find. Living right in New York. I just think that's amazing.

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Life Sometimes

You ever had one of those days when you just have so many things to do, but you just want to lay back and relax because you've been busy for the past few days and will continue to be busy in the near future.?  Of course you have, everybody has those days.  I had one of those days today.  I was walking all over town to get to classes, and to do other errands, which had to be done today, because I have work the next couple days, so I really don't have any other option than to do everything in one day  Maybe it's because I just haven't gotten the routine down yet, but I'm honestly just completely exhausted.  I hate making complaints like this public, but this is all I can really think about right now, so that's what I'm writing about.  Hopefully nominal service will return tomorrow, but right now, I just want to get to sleep.  Unfortunately, I still have some reading to do.  Ah well, such is college.

A Year of Curiosity

The Curiosity rover has been on Mars for a year now.  While the rover captured the public's eye with its exciting landing, I've been waiting for a while, watching the science roll in.  This article provides a good summary of everything that the probe has accomplished in the past year:

http://www.wired.com/wiredscience/2013/08/curiosity-year-discoveries/?pid=9781&viewall=true

The confirmation that Mars had fresh liquid water at its surface is the most exciting piece of news.  The implications should be obvious, where there is water, life usually follows.  Unfortunately, Curiosity isn't equipped to look for ancient or current life, so we'll have to wait for the next rover to find the answer to those questions.  However, the prospects for current life on Mars do not look good, as Curiosity was unable to detect any methane in the Martian atmosphere.  Methane had previously been detected, and since methane almost always comes from an organic source, modern life on Mars seemed likely.  This result doesn't mean there isn't currently life on Mars, but the odds are against it.  The rover is still going strong, and hopefully the future will prove to be as productive as the past year for Curiosity.